TWI516743B - Autofocusing 3d measurement system with linear nanopositioning function - Google Patents

Description

Autofocus three-dimensional measuring system with linear nano positioning

The invention relates to a three-dimensional measuring system, in particular to a three-dimensional measuring system with linear nano positioning and automatic focusing.

The development of non-contact probes is based on the optical principle and is combined with electronic signal processing technology to achieve various measurement purposes. According to the detector, it can be divided into an optical switching sensor, a CCD (Coupled Charged Device) imaging technology, and a PSD (Position Sensitive Detector) detection method. The principle of the optical switching probe is similar to the mechanical triggering probe. The trigger source is from the optical shadow mask, which is generally used for edge detection or position detection. Since the CCD is composed of a separate photosensitive element, the CCD image capturing technique tends to be discontinuous. The accuracy is determined by the speed and mode of the signal, in addition to the magnification of the mirror. The PSD detection method is a detection method for detecting the position of an incident point by using a laser optical probe. Compared with the CCD image capturing technology, the PSD detection method has the advantages of high position recognition, fast response speed, simple signal processing, and the PSD detection method. The analog signal is continuously output, and the position output signal is only related to the position of the incident light. Its structure is relatively simple, so it is especially suitable for the measurement of the surface of the object to be tested.

At present, mature laser optical probes include laser triangulation measurement method, laser confocal feedback method, laser scattering method and laser interferometer (Heterodyne Interferometer). However, at present, most of these instruments rely on foreign manufacturers to import, and the cost is expensive and bulky. Therefore, many scholars have proposed to use the image to measure the three-dimensional contour of the object, and to obtain the object by CCD movement, CCD spin, etc. Depth, except that the captured image is non-continuous, the measured image results will have a staircase effect, resulting in a wrong judgment on the measurement.

The main object of the present invention is to provide an autofocus three-dimensional measuring system with linear nano positioning, which is mainly for obtaining the size of the surface contour of a small object to be tested through the system. That is, the one-dimensional measuring component is combined with the two-dimensional measuring component to obtain the three-dimensional size of the object to be tested, and a piezoelectric component is used as an actuator to drive the linear movement of the linear nanopositioning device, and simultaneously drive the three-dimensional measurement. Device, when the height of the surface of the object to be tested changes When the defocus signal is used as the judgment value, the piezoelectric element is driven to drive the linear nano positioning platform, so that the system achieves a wide range of auto focus measurement.

The above-mentioned main object and effect of the present invention are achieved by the following specific technical means: an automatic focusing three-dimensional measuring system with linear nano positioning, comprising a piezoelectric actuating element, a linear nano positioning device, a three-dimensional a measuring device and a processing unit; the piezoelectric actuating element has an output end; the linear nano positioning device comprises two lever elements and two curved arm elements, each of the two lever elements having a corresponding first end and a second end, a fulcrum is disposed between the first end and the second end, and the first end of the two lever elements is connected to the output end of the piezoelectric actuating element; the two curved arm elements respectively have corresponding a first end and a second end, the first end of the two curved arm members being pivotally connected to the second end of the two lever members, and the second ends of the two curved arm members being pivotally connected to each other; the three-dimensional measuring device The invention comprises a one-dimensional shape sensing component, a two-dimensional image measuring component, an imaging lens, a first light source, a non-polarizing beam splitter, a polarizing beam splitter and a microscope objective lens; the polarizing beam splitter is placed in a one-dimensional shape Between the sensing element and the microscope objective, the non a polar spectroscope is disposed on a side of the polarizing beam splitter, the imaging lens is located between the two-dimensional image measuring component and the non-polarizing beam splitter, and the light of the first light source is projected on the surface of the object to be tested and reflected back The three-dimensional measuring device; the one-dimensional shape sensing element along with the object to be tested The undulation of the surface can obtain an out-of-focus signal; thereby, the one-dimensional shape sensing component and the two-dimensional image measuring component respectively measure one-dimensional surface contour data and two-dimensional surface contour size data of the surface of the object to be tested; Processing unit, after receiving the defocus signal, performing an arithmetic process to obtain a focus drive signal, and driving the piezoelectric actuator to change an output state according to the focus drive signal; and the processing unit simultaneously integrates the measured object to be tested One-dimensional surface contour data and two-dimensional surface contour size data to obtain the three-dimensional size of the object to be tested.

The automatic focus three-dimensional measuring system with linear nano positioning as described above, wherein the one-dimensional optical displacement sensing device comprises a second illumination source, a beam splitter, a mirror, a collimating mirror and a light sensation a second illuminating source emits a beam of light toward the spectroscope through the mirror and penetrates the collimating mirror, and the beam passes through the polarizing beam splitter and the microscope objective to focus on the object to be tested. The reflected beam is then projected onto the photosensor through the microscope objective, the polarizing beam splitter, the collimating mirror, the mirror, and the beam splitter.

An autofocus three-dimensional measuring system with linear nanopositioning as described above, wherein the second illumination source is a laser diode.

An autofocus three-dimensional measuring system with linear nanopositioning as described above, wherein the beam splitter is composed of a second polarizing beam splitter and a quarter wave plate for polarizing the beam and changing The direction of travel of the beam.

The automatic focus three-dimensional measuring system with linear nano positioning as described above, wherein the photo sensor is a four-quadrant light sensor.

(1) ‧‧‧ Piezoelectric actuating components

(11)‧‧‧ Output

(2)‧‧‧Linen nano positioning device

(21)‧‧‧Leverage components

(211) ‧‧‧ first end

(212) ‧‧‧ second end

(213) ‧ ‧ fulcrum

(22)‧‧‧Flex arm components

(221) ‧‧‧ first end

(222) ‧‧‧ second end

(3) ‧‧‧3D measuring device

(31)‧‧‧One-dimensional topographical sensing elements

(311)‧‧‧second source of illumination

(312)‧‧‧beam splitter

(3121)‧‧‧Second polarized beam splitter

(3122)‧‧‧ Quarter Wave Plate

(313)‧‧‧Mirror

(314)‧‧‧ Collimation mirror

(315) ‧‧‧Photosensor

(32)‧‧‧Two-dimensional image measuring components

(33)‧‧‧ imaging lens

(34) ‧‧‧first source of illumination

(35)‧‧‧Non-polar polarizing mirror

(36) ‧‧‧polar polarizer

(37)‧‧‧Microscope objective

(4) ‧‧‧Processing unit

(O)‧‧‧First direction

(P)‧‧‧second direction

The first figure: the block diagram of the autofocus three-dimensional measurement system with linear nano positioning in the present invention

Second: Schematic diagram of the structure of the linear nano positioning device of the present invention

Third: Schematic diagram of the architecture of the three-dimensional measuring device of the present invention

Fourth figure: Schematic diagram of the structure of a dimensional shape sensing component of the present invention

For a more complete and clear disclosure of the technical content, the purpose of the invention and the effects thereof achieved by the present invention, it is explained in detail below, and please refer to the drawings and drawings:

Please refer to the first figure, which is a schematic diagram of the architecture of the autofocus three-dimensional measuring system with linear nano positioning according to the present invention.

The automatic focusing three-dimensional measuring system with linear nano positioning of the invention comprises a piezoelectric actuating element (1), a linear nano positioning device (2), a three-dimensional measuring device (3) and a processing unit ( 4); where:

The piezoelectric actuating element (1) has an output (11) (see the second figure).

The linear nano positioning device (2) comprises two lever elements (21) and two curved arm elements (22) respectively located at the output end of the piezoelectric actuating element (1) ( On both sides of the 11), the lever member (21) has a corresponding first end (211) and a second end (212), and a first end (211) and the second end (212) are disposed between the first end (211) and the second end (212) a fulcrum (213), such that the first end (211) and the second end (212) can be operated in a high-low state like a seesaw due to the setting of the fulcrum (213); the two lever elements (21) The first end (211) is connected to the output end (11) of the piezoelectric actuator (1); the two curved arm elements (22) each have a corresponding first end (221) and a second end (222), the first end (221) of the two curved arm members (22) is pivotally coupled to the second end (212) of the lever member (21), and the second end of the two curved arm members (22) 222) are pivoted to each other. The equivalent mechanism diagram simplified by the linear nanopositioning device (2) of the present invention, and the theoretical magnification and displacement are analyzed by a rigid body, and the relative relationship of the formula (1) can be obtained: d = a ₁ (cos θ ₁ + a ₂ sin θ ₁ ) d _p (1)

Where a ₁ = l ₁ / l ₀ is the lever magnification, a ₂ = l ₁ / tan θ is the elbow magnification, d _p is the actuator input displacement, and d is the final output displacement.

The three-dimensional measuring device (3) (please refer to the third figure) is set on the straight line The second end (222) of the two-curved arm member (22) of the nano-positioning device (2) is pivoted to drive the three-dimensional measuring device (3) to be directly displaced by the linear nano-positioning device (2). Adjusting the focus position of the three-dimensional measuring device (3); the three-dimensional measuring device (3) comprises a one-dimensional shape sensing component (31), a two-dimensional image measuring component (32), an imaging lens (33), and a first light emitting Source (34), non-polarizing beam splitter (35), polarizing beam splitter (36), microscope objective (37); the polarizing beam splitter (36) is placed in a one-dimensional shape sensing component (31) and display Between the micro objective lens (37), the non-polarizing beam splitter (35) is placed on one side of the polarizing beam splitter (36), and the imaging lens (33) is located at the two-dimensional image measuring component (32) and the non- Between the polarizing beamsplitters (35), the light of the first light source (34) is directly projected on the surface of the object to be tested, and the reflected light is received by the three-dimensional measuring device (3), and the one-dimensional shape sensing The beam generated by the component (31) is projected onto the surface of the object to be tested by the polarizing beam splitter (36) and the microscope objective lens (37), and then the beam reflected back from the surface of the object to be tested is returned according to the original route, and is analyzed and operated. After obtaining the surface profile of the object to be tested; The two-dimensional image measuring component (32) directly projects the light from the first light source (34) on the surface of the object to be tested, and the light beam reflected from the surface of the object to be tested is returned to the beam through the microscope objective (37). The polar spectroscope (36), the non-polar polarizing beam splitter (35), and the imaging lens (33) are imaged on the two-dimensional image measuring component (32) to instantly capture the image of the surface of the object to be tested, and obtain the object to be tested. The two-dimensional surface contour size; the one-dimensional top sensing element (31) obtains an out-of-focus signal along with the undulation of the surface of the object to be tested.

Wherein (see Figure 4), the one-dimensional topographical sensing component (31) includes There is a second illumination source (311), a beam splitter (312), a mirror (313), a collimating mirror (314) and a photo sensor (315); the second illumination source (311) is a a laser diode, the emitted light beam is directed toward the beam splitter (312), and the beam splitter (312) is composed of a second polarizing beam splitter (3121) and a quarter wave plate (3122). Polarizing the beam and changing the direction of travel of the beam. After the beam passing through the beam splitter (312) passes through the mirror (313) and penetrates the collimating mirror (314), the beam passes through the polarizing beam. The mirror (36) and the microscope objective (37) are focused on the object to be tested, and the reflected beam passes through the microscope objective (37), the polarized beam splitter (36), and the collimating mirror. 314), the mirror (313), the beam splitter (312) is projected onto the four-quadrant light sensor (315); and when the surface of the object to be tested is located at the microscope objective (37) When the focus plane is on, the reflected light of the second illumination source (311) is passed through the collimating mirror (314), the mirror (313) and the beam splitter (312) on the four-quadrant light sensor (315). Forming a circular area (focus signal); if the surface of the object to be tested is located in the display The unfocused area of the objective lens (37) is shaped by the collimating mirror (314), the reflecting mirror (313) and the reflected light of the beam splitter (312) on the four-quadrant light sensor (315). Then, it is an elliptical shape (out of focus signal); and the four-quadrant light sensor (315) sends the sensed signal to the processing unit (4) to determine whether the three-dimensional measuring device (3) is out of focus. .

The processing unit (4), after receiving the signal from the four-quadrant light sensor (315), determines whether the three-dimensional measuring device (3) is in focus or loss. a focus state, when the processing unit (4) determines that the three-dimensional measuring device (3) is out of focus, a focus drive signal is simultaneously generated, and the processing unit (4) drives the piezoelectric actuator element according to the focus drive signal (1) causing the piezoelectric actuator (1) to change its output (11) state; the processing unit (4) simultaneously integrating the one-dimensional of the object to be tested measured by the three-dimensional measuring device (3) The surface contour data and the two-dimensional surface contour size data are obtained to obtain the three-dimensional size of the object to be tested.

When implemented (please refer to the first to fourth figures), firstly, the laser light of the second illumination source (311) is focused on the mirror (313) by using the one-dimensional shape sensing component (31), and the reflected light source is reflected. Projected in the four-quadrant light sensor (315), while adjusting the distance between the collimating mirror (314) and the mirror (313), so that the light spot of the four-quadrant light sensor (315) has the same distribution in the four quadrants. This reaches the focus and fixes the position of the three-dimensional measuring device (3). Then, the object to be tested is placed to an appropriate position, and the distance between the object to be tested and the microscope objective (37) is adjusted, so that the three-dimensional measuring device (3) reaches the state of focusing; when the focusing is completed, the one-dimensional shape is utilized. The sensing element (31) is used as a measure of the surface depth of the object to be tested, and at the same time, the two-dimensional image measuring element (32) is used for measuring the surface profile. The one-dimensional shape part is the characteristic of the linear region of the curve measured by the one-dimensional shape sensing component (31), and the relationship between the position and the voltage output is established, and the change of the displacement amount is known; and the two-dimensional image measuring part is obtained. Then, the image extracted by the two-dimensional image measuring component (32) is pre-processed, and the processed image is introduced into the measurement formula, so that the geometric shape of the object to be measured can be quantified by the pixel, and then Calculate the size of the original DUT with the imaging principle. In addition, by driving the piezoelectric The moving element (1) drives the linear nanopositioning device (2) to adjust the distance between the three-dimensional measuring device (3) and the object to be tested. That is, when the surface height of the object to be tested changes, the distance between the three-dimensional measuring device (3) and the object to be tested changes, causing the three-dimensional measuring device (3) to be out of focus. At this time, the processing unit (4) The out-of-focus signal is used as a judgment value and a focus drive signal is obtained to drive the piezoelectric actuator (1) in accordance with the focus drive signal. When the output end (11) of the piezoelectric actuator (1) protrudes in the first direction (O), the first end (211) of the lever member (21) is associated with the piezoelectric actuator (1) The output end (11) is connected such that the first end (211) of the lever member (21) is driven in the first direction (O), and the second end (212) of the lever member (21) is due to the fulcrum ( 213) the relationship, and moving in the second direction (P), at this time because the first end (221) of the crank arm member (22) is pivotally connected with the first end (211) of the lever member (21), and two songs The second ends (222) of the arm members (22) are pivotally connected to each other such that the position of the pivotal connection of the second end (222) of the two curved arm members (22) is displaced in the second direction (P), and thus drives the three-dimensional The measuring device (3) enlarges the distance between the object to be tested; when the output end (11) of the piezoelectric actuator (1) is retracted in the second direction (P), the lever member (21) The first end (211) will be driven in the second direction (P), so that the second end (212) of the lever member (21) moves in the first direction (O) due to the fulcrum (213), and the interlocking The position of the pivotal position of the second end (222) of the arm member (22) is displaced in the first direction (O), and the three-dimensional measuring device (3) is brought closer to the object to be tested. The distance; thereby achieving the effect of auto focus measurement.

The above is only a part of the embodiments of the present invention, and is not intended to limit the present invention. It is intended to be included in the scope of the present invention.

In summary, the embodiments of the present invention can achieve the expected use efficiency, and the specific technical means disclosed therein have not been seen in similar products, nor have they been disclosed before the application, and have completely complied with the patent law. The regulations and requirements, the application for invention patents in accordance with the law, and the application for review, and the grant of patents, are truly sensible.

(1) ‧‧‧ Piezoelectric actuating components

(2)‧‧‧Linen nano positioning device

(3) ‧‧‧3D measuring device

(4) ‧‧‧Processing unit

Claims (5)

An automatic focusing three-dimensional measuring system with linear nano positioning includes a piezoelectric actuating element, a linear nano positioning device, a three-dimensional measuring device and a processing unit; the piezoelectric actuating element has an output end; The linear nano positioning device comprises two lever elements and two curved arm elements, each of the two lever elements having a corresponding first end and a second end, and a branch point is arranged between the first end and the second end a first end of the two lever members connected to an output end of the piezoelectric actuation element; the two curved arm members each having a corresponding first end and a second end, the first end of the two curved arm members The second ends of the two lever members are pivotally connected, and the second ends of the two curved arm members are pivotally connected to each other. The three-dimensional measuring device comprises a one-dimensional shape sensing component, a two-dimensional image measuring component, an imaging lens, a first illuminating source, a non-polarizing beam splitter, a polarizing beam splitter, and a microscope objective; the polarizing beam splitter is disposed between the one-dimensional shape sensing component and the microscope objective, and the non-polarizing beam splitter is disposed on the polarizing pole One side of the beam splitter, the imaging lens is located in the two-dimensional shadow Between the measuring component and the non-polarizing beam splitter, the light of the first light source is directly projected on the surface of the object to be tested; the one-dimensional optical displacement sensing device comprises a second light source, a beam splitter, a mirror, a collimating mirror and a photo sensor; the second illuminating source emits a beam of light toward the spectroscope through the mirror and penetrates the collimating mirror, and the beam passes through the polarizing beam splitter and the microscope objective Focus On the object to be tested, the reflected beam is then projected onto the photosensor through the microscope objective, the polarizing beam splitter, the collimating mirror, the mirror, and the beam splitter; The dimensional shape sensing component can obtain an out-of-focus signal along with the fluctuation of the surface of the object to be tested; thereby, the one-dimensional shape sensing component and the two-dimensional image measuring component respectively measure the one-dimensional surface contour of the surface of the object to be tested Data and two-dimensional surface contour size data; the processing unit performs an arithmetic process after receiving the out-of-focus signal to obtain a focus drive signal, and drives the piezoelectric actuator to change an output state according to the focus drive signal; the processing unit At the same time, the measured one-dimensional surface contour data and the two-dimensional surface contour size data of the object to be tested are integrated to obtain the three-dimensional size of the object to be tested. The automatic focusing three-dimensional measuring system with linear nano positioning as described in claim 1, wherein the second light source is a laser diode. An autofocus three-dimensional measuring system with linear nanopositioning as described in claim 1 or 2, wherein the beam splitter is composed of a second polarizing beam splitter and a quarter wave plate, and is used for The beam is polarized and the direction of travel of the beam is changed. An autofocus three-dimensional measuring system with linear nanopositioning as described in claim 3, wherein the photo sensor is a four-quadrant photosensor. An autofocus three-dimensional measuring system with linear nanopositioning as described in claim 1 or 2, wherein the photo sensor is a four-quadrant photosensor.